1. Field of the Invention:
This invention relates to the manufacture of ophthalmic lenses and has particular reference to the finishing of cut and/or ground lens surfaces.
2. Discussion of the Prior Art:
Ophthalmic lens surfaces which are machined to prescription curvatures with cutting tools and/or loose abrasives exhibit tool and/or abrasive marks which produce the well-known "gray" effect needing to be removed by further working.
Heretofore, removal of machined surface roughness has required fine grinding and polishing operations which are time consuming, tedious and costly to perform and require large investment in capital equipment. Additionally, in the manufacture of plastic opthalmic lenses which are conventionally fine ground and polished, it is considered desirable, if not necessary, to incur the additional manufacturing time and cost of covering the polished surfaces with a tough and optically clear material for enhancement of scratch resistance as disclosed in U.S. Pat. Nos. 3,986,997 and 4,127,697, for example.
In view of the aforesaid drawbacks of prior art high capital equipment cost, undue expenditure of manufacturing time and other high costliness of finishing machined ophthalmic lens surfaces, it is a principal object of this invention to provide a lens surface finishing operation which obviates the need for much, if not all, of the traditional finishing equipment and procedures and wherewith an optimum optically clear, highly scratch resistant lens surface may be produced simply, rapidly and economically.
More specifically, it is an object of the invention to provide optically clear finishes on machined lens surfaces without the need for lens polishing operations; and
Another object is to accomplish the foregoing with simultaneous provision of end product high scratch resistance.
Other objects and advantages of the invention will become apparent from the following description.